Bleaching glue.



UNITED sTArss r a rENfT OFFICE.

ARMAND JULIUS S'lTIl'lGELlWA NN AND ERICII DETINEL, Ol LUDWlGSliAl EN-ON-TIIE-RIIINE, GERMANY, ASSIGNORS T BADI'SCIIE ANlLlN & SODA l ABltlK. 0h LUDWlGSllAFEN-ON- TIIILRTII'NE, GERMANY, A CORPORATION.

BLEACHING G-LUE.

Specification of Letters Patent.

Application filed Julie 13,1907. Serial No 378,874.

Patented Sept. 24, 1907.

To all whom it may concern:

Be it known that we, ARMAND J ULIUs STIEGELMANN and Enron DEHNEL, doctors of philosophy and cheniists, subjects of the German Emperor, residing at Ludwigshai'en-on-the-Rhine, Germany, have invented new and useful Improyemonts in Bleaching Glue, of which the following is a specification.

We have discovered that glue can .be satisfactorily blcachedby treatment with zinc formaldehyde sulfoxylate. In carrying out 011/ invention we may make use eithenof the so-called basic zinc formaldehyde sulfoxylate described and claimed in the specification of Letters Patent No. 812,124, or of. neutral zinc formaldehyde sulfoxylate. The bleaching can be carried out by heating a solution of the glue with either of the said our invention may be carried out for example as foll0 ws but it is not confined to this example. Add to a solution containing glue, at-a temperature of about one hundred (100) degrees Centigrade, and while stirring,

a thin paste of basiczinc formaldehyde sulfoxylate, using about two (2) parts by weight thereof for every thousand (1,000) parts by weight of the finished glue. The bleaching is effected in a few minutes, and'tbe product can be worked up as usual. In this example,

instead of the thin paste of two parts of the basic zinc salt, a solution of about four (4) parts of the neutral vine formaldehyde sulloxylate can be employed. Ii desired, an acid (for instance acetic acid, formic acid, or sulfuric acid) may be added either to the mixture or to the glue solution, before the addition of the zinc salts.

Now what we claim is: 1. The process of bleaching glue which consists in treating the glue with zinc formaldehyde sulfoxylate in the presence of water. 40

2. The process of bleaching glue which consists in treating the glue with basic zinc formaldehyde sulfoxylate in the presence of water.

3. The process of bleaching glue which consists in treating the glue with basic zine formaldehyde sulfoxylate in the presence of water and acid.

In testimony whereof we have hereunto set our hands in the presence of two subscribing witnesses.

ARMAND JULIUS SYIPIEGELMANN. ERICH DFJHNEL. Witnesses l hmns'r F. Enmmnnr, 1. Anne. Tmorn. 

